One of the simplest methods of recording and communicating information is the traditional method of writing the information on a piece of paper with a writing instrument such as a pen. Writing information by hand on a piece of paper is inexpensive and can be done quickly and easily with little preparation. The traditional method is also flexible in that a writer generally can write in any format anywhere on the page. One of the limitations with handwritten work is that it is not easily manipulated or transferred to other contexts. In other words, changing or transferring a piece of handwritten script typically requires rewriting the script on another medium.
With the widespread use of personal computers, textual information often is recorded using word processing software running on a personal computer. The advantage of such electronic methods of recording information is that the information can be stored easily and transferred to other remote computing devices and electronic media. Such electronically recorded text also can be easily corrected, modified, and manipulated in a variety of different ways.
Typical computer systems, especially computer systems using graphical user interface (GUI) systems such as Microsoft WINDOWS, are optimized for accepting user input from one or more discrete input devices. Common input devices include a keyboard for entering text and a pointing device, such as a mouse with one or more buttons, for controlling the user interface. The keyboard and mouse interface facilitates creation and modification of electronic documents including text, spreadsheets, database fields, drawings, and photos.
One of the limitations with conventional GUI systems is that a user must generally type the text they are entering into the personal computer using the keyboard. Entering text using a keyboard can be slower and more cumbersome than handwriting. Although recent advances have been made in reducing the size of personal computers, they are still not as portable and easily accessible as traditional pen and paper. Furthermore, traditional pen and paper provide the user with considerable flexibility for editing a document, recording notes in the margin, and drawing figures and shapes. In some instances, a user may prefer to use a pen to mark-up a document rather than to review the document on-screen, because of the ability to freely make notes outside of the confines of the keyboard and mouse interface.
To address the shortcomings of traditional keyboard and mouse interfaces, there have been various attempts to create an electronic tablet that can record handwriting. The electronic tablets typically comprise a free-form document editor for creating free-form documents, which is considered a valuable tool for enabling a user to engage in free-form note taking. The electronic tablets typically also comprise a screen and a handheld device that is similar to a pen. A user can write with the handheld device on the screen of the electronic tablet in a similar manner to traditional pen and paper. The electronic tablet can “read” the strokes of the user's handwriting with the handheld device and recreate the handwriting in electronic form on the screen with “electronic ink.” That electronic tablet approach can be employed in a variety of ways, including on a personal computer and on a handheld computing device.
Recently, other computer systems have been developed that provide for more sophisticated creation and manipulation of electronic ink. Those applications (for example, drawing applications associated with Palm and PocketPC operating systems) can permit the capturing and storing of drawings. Those drawings include other properties associated with the ink strokes used to make up the drawings. For instance, line width and color may be stored with the ink. One goal of these systems is to replicate the look and feel of physical ink being applied to a piece of paper. However, physical ink on paper can have significant amounts of information not captured by the electronic collection of coordinates and connecting line segments. Some of this information may include outline structure and type of writing (such as handwriting or drawing).
In spite of the advances in electronic tablets and electronic ink, there are still several limitations with the performance of such electronic handwriting devices. For example, conventional free-form document editors cannot recognize document structure as the user inputs ink strokes on the tablet. Each line of handwriting is converted separately to text and aligned along a left margin of the screen. Accordingly, any indented formatting provided by the user for the ink strokes is lost on conversion to text.
Another problem with conventional free-form document editors is the blind conversion of ink to text. For example, ink can be converted to text and located in the screen in the exact location of the input ink strokes. However, that method merely provides electronic text without linking the text throughout the electronic document. Accordingly, the user cannot revise and edit the electronic text when it is converted in that manner. Additionally, the text cannot always be exported to other application programs such as a word processor application program.
Another problem with conventional free-form document editors is a lack of feedback regarding the type of ink input by the user. The types of ink include handwriting and drawing. The editor may erroneously classify handwriting as a drawing. However, the editor cannot indicate the classification to the user. Accordingly, the user does not know of the error until the user realizes that the ink was not converted to text. By that time, many lines of ink may be erroneously classified, causing excess work by the user to correct the formatting.
Accordingly, there is need in the art for improving handwriting recognition and conversion in free-form electronic documents. A further need exists for providing feedback regarding the free-form document editor's classification of handwritten ink strokes. Additionally, a need exists in the art for guiding the user's ink input to increase text recognition accuracy. A need also exists for allowing a user to input structured formatting for handwriting and for converting the formatting into text usable by other application programs.